Supt Langdon added: “We don’t believe it is terrorist related at this stage.

“Investigations are obviously still going on.

“We believe the male, the 25-year-old male from Dandenong, has acted alone.

“We are currently finalising our process of investigation of the passengers and the crew.

“It’s an electronic object but it was soon recognised not to be an explosive device.

“We are aware that this gentleman has mental health issues.

“I think it is quite heroic by the passengers and the crew to restrain him in the way they’ve done.

“We have done everything we can and I know Malaysian Airlines have done everything they can to try to help get the passengers through this process and be able to return home or get on to other flights.”

In a statement released this morning, Malaysia Airlines says: “MH128, which had departed Melbourne Airport at 11.11pm and was scheduled to arrive Kuala Lumpur at 5.28am on 1 June, made a turn back to Melbourne after the operating Captain was alerted by a cabin crew member of a passenger attempting to enter the cockpit.

“Malaysia Airlines would like to stress that at no point was the aircraft ‘hijacked’.

“MH128 safely landed in Melbourne airport at 11.41pm.

“Following the incident on MH128, the disruptive passenger has been apprehended by airport security.

“Malaysia Airlines together with the Australian authorities will be investigating the incident.

“Safety and security are of utmost priority to Malaysia Airlines.

“The airline wishes to apologise for the inconvenience caused.

“Passengers have safely disembarked the aircraft and will be screened by Australian authorities.

“Affected passengers will be accommodated at hotels.

“They will be offered travel on the next available flight or on other carriers.”

Victoria Police Senior Constable Adam West said police were called to Tullamarine at 11.40pm last night after Malaysia Airlines requested help.

“It is alleged that a man tried to enter the cockpit and threatened the safety of passengers and staff,” he said.

“It was huge, it was black and it had two black antennaes coming off it, but it also looked like an iPhone jack,” he said.

Federal Transport Minister Darren Chester said early information indicated the security screening measures were working ahead of the flight and onboard.

The Minister said there were “very strict” security protocols in place in Australia but said the incident would be reviewed.

He said it was too early to comment on the device the man was holding.

“By all early accounts, the security parameters worked but that doesn’t change the fact it would have been a very worrying time for the passengers and crew on board when the incident occurred,” he told the ABC.

Mr Chester said the incident did not appear to be terrorism-related but rather a mental health issue.

“We are reviewing our security procedures in response to new information, new alerts around the world on an ongoing basis,” he said.

“Obviously the security of the Australian travelling public is the highest priority when it comes to Transport Ministry issues.

“If we receive new information, or there is a new or emerging threat around the world, we assess our protocols accordingly.

“We have outstanding security protocols here in Australia. It is designed to keep the travelling public safe.

“We have to look at this incident and review every aspect of it and then make an assessment about whether any changes need to be made.”

Mr Chester said there were no plans currently to introduce bans on a laptop or large electronic devices on planes similar to bans introduced in the United States and United Kingdom.

MH128, which had departed Melbourne Airport at 11.11pm scheduled to arrive Kuala Lumpur at 5.28am on 1 June, made a turn back to Melbourne after the operating Captain was alerted by a cabin crew of a passenger attempting to enter the cockpit.

Malaysia Airlines would like to stress that at no point was the aircraft 'hijacked'.

MH128 safely landed in Melbourne airport at 11.41pm.

Following the incident on MH128, the disruptive passenger has been apprehended by airport security. Malaysia Airlines together with the Australian authorities will be investigating the incident.

Safety and security are of utmost priority to malaysia airlines. The airline wishes to apologise for the inconvenience caused.

Passengers have safely disembarked the aircraft and will be screened by Australian authorities.

They will be accommodated at hotels and offered on the next available flight or on other carriers.